Lens adjustment
Under lens adjustment (engl. Lensshift) also oblique projection means is a function of projectors referred to in which the lens can be adjusted to avoid a trapezoid distortion with optical means at an oblique projection.
function
Lens adjustment is a function of projectors in which the lens can be moved parallel to the original projection (LCD, slide, etc.) for an oblique projection. As a result, an orthogonal representation on the projection template is also projected orthogonally onto the screen .
The objective of lens adjustment is to avoid trapezoidal distortion with optical means. This avoids the disadvantages of digital compensation, such as reduced resolution, staircase artifacts or reduced light intensity .
Depending on the design of the projector, the lighting unit must also be moved accordingly. As a result, the light source is shown in the center of the shifted lens. Not every lens is suitable for lens adjustment. The lens needs a large image circle for adjustment. Angled projection is possible for both horizontal and vertical use.
Applications
- Film projection from the projection booth to the lower-lying vertical screen.
- Video projection without losses due to digital compensation.
- Work projection in training and teaching, angles or a curve shape are retained on the screen.
Individual evidence
- ↑ Wolfgang Grau: Technique of the projection. Beuth Verlag GmbH, Berlin 1994, page 488, ISBN 3-410-13194-9 .